120mm Fan low profile grid (screw & screwless)

thingiverse

Humans can 3D print on a 2mm thick grid without needing print supports. The Honeycomb pattern they use is big enough that it's not finger-friendly to touch after printing, and PLA often requires them to detach it by sliding a sheet of paper under the part to avoid sticking it to the bed. As long as holes are placed at least 7mm from any corners, the SCAD file will work with fans of any size.